Re: Maxon OD9 vs OD808.. vs TS808 RI!
I have the OD-9, and when I bought it I compared it to the OD-808. IMO both pedals have about the same amount of gain available. The OD-808's tone was a bit "sweeter" and slightly smoother than the OD-9, although the OD-9 sounds nice, too. The on/off switch on the OD-9 must be pressed just right to operate it. (If you don't push it down far enough it won't turn on or off.) The switch on the OD-808 is very easy to operate, but IMO feels cheap and fragile. The OD-9 is true bypass, and the OD-808 is not.
I preferred the sound of the OD-808, but bought the OD-9 because of the better switch (IMO) and true bypass.
Note: I suck at describing sounds, so consider my opinion at your own risk!